Apparatus for and method of manufacturing multi-ply bags



Dec. 6, 1966 A. J. ClVlTELLO APPARATUS FOR AND METHOD OF MANUFACTURINGMULTI-PL-Y BAGS 5 Sheets-Sheet 1 Filed March 19, 1965 2 XQQ W .I P em &W

ANTHONY J. CIVITELLO A. J. CIVITELLO Dec. 6, 1966 APPARATUS FOR ANDMETHOD OF MANUFACTURING MULTI-PLY BAGS Filed March 19. 1965 5Sheets-Sheet 2 .INVENTOR ANTHONY J. CIVITELLO ATTORNEYS A. J. CIVITELLODec. 6, 1966 APPARATUS FOR AND METHOD OF MANUFACTURING MULTI-PLY BAGS 5Sheets-Sheet 5 Filed March 19, 1965 Dec. 6, 1966 A. J. CIVITELLO3,239,915

APPARATUS FOR AND METHOD OF MANUFACTURING MULTI-PLY BAGS Filed March 19,1965 5 Sheets-Sheet 4 2I8 233 2|6 f (204 Q A) Q7 ,r?'

INVENTOR ANTHONY J. CIVITELLO w .2 W J Z/4'L LJI-L\,- (A -"11M, mid/2X MM ATTORNEYS Dec. 6, 1966 A. J. CIVITELLO APPARATUS FOR AND METHOD OFMANUFACTURING MULTI-PL-Y BAGS Filed March 19, 1965 5 Sheets-Sheet 5 wmmwmm

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v ilmmmwfl I I A L M mwmk Q vwm mflm 6m m Y llw m\ 0mm mmmi mom mmm u Nm\/ /M./ MOM mom QM ANTHONY J CSVITELLO United States Patent Oflice3,289,915 Patented Dec. 6, 1966 3,289,915 APPARATUS FOR AND METHGD FMANU- FACTURLNG MULTf-PLY BAGS Anthony J. Civitello, Malvern, Pa,assignor to Continental Can Company, Inc., New York, N.Y., a corporationof New York Filed Mar. 19, 1965, Ser. No. 441,175 16 Claims. (Cl.229-59) This invention relates to improvements in paper bags of themulti-ply type which generally include at least an outer wrapper and aninner liner, and is particularly dirooted to a novel apparatus for and amethod of fabrieating multi-ply bags having bottom constructions formedby adhesively securing together a plurality of closure flaps in a mannerunprovided for by known bag manufacturing apparatuses and methods toform a stronger and more efficient bag construction than has beenheretofore available.

The most simple conventionally fabricated multiply bag is a two-plystructure having an inner liner and an outer wrapper. Such a bag iscustomarily fabricated from two separate but continuous webs. Theinvention is particularly concerned with the specific type of multi-plybag wherein the web forming the liner is of a grease-resistant,moisture-proof material while the web forming the wrapper is of aheavy-gage paperstock material to provide the requisite bag strength.The two separate webs of material are drawn simultaneously from twoseparate rolls and are fed by a conveyor mechanism in parallel,superimposed, relationship at identical speeds on the order of 200300feet per minute.

It is customary to feed the two webs in a manner in which one of thewebs is transversely offset with respect to the other. That is, alongitudinal edge of one of the webs extenils transversely beyond alongitudinal edge of the other of the webs. The purpose for thistransverse offset is to form staggered longitudinal seams in bags formedfrom the webs, which, due to the staggered relationship, reinforce thebags and provide a tortuous path for material tending to sift out of theinner liner through the outer wrapper of each so-formed bag.

The rapidly advancing webs are drawn through an adhesive applyingmechanism which applies adhesive to the two webs to form a singletwo-ply web having staggered longitudinal edges.

A shear or die intermittently traverses the adhesively joined two-plyweb and severs the web into two consecutive blank assemblies having topand bottom transverse edges. Each individual blank assembly is formedinto -a tube and the longitudinal edges of each ply are adhesivelyjoined together to form the staggered longitudinal seams of the bags.The bottom of the tube is then folded in any one of a variety ofdifferent ways to complete the fabrication of the bag.

In all such prior art multi-ply bags with no known exceptions, the innercoated surface of the liner at one flap is brought into overlyingadhesive contact with an outer surface of the wrapper at another flap toform the final closure of the bag bottom construction. Because the innersurface of the liner is coated with, for example, polyethylene or otherrelatively impermeable material, the water of conventionally employedwater-based adhesive is not absorbed by the coated inner liner resultingin excessive setting up time for the manufacture of such bags. Inaddition, the impermeable and generally non-wettable nature of suchcoatings on the liners prevent the adhesive from effectively adhering tothe liner and thus precludes the formation of a strong seal between theliner and that portion of the wrapper to which the liner flap isoverlaid.

It is, therefore, a primary objective of this invention to provide animproved multi-ply bag having a bottom construction of the type whichincludes an outer wrapper and an inner liner formed into overlying innerand outer closure flaps, a portion of the liner of the outer closureflap being folded upon itself to expose an inner surface of the outerwrapper of the outer closure flap and an outer surface of the liner tothe outer surface of the inner closure flap whereupon adhesive appliedto these surfaces provides an efiicient and strong bottom constructionby efitecting an adhesive bonding between only uncoated paper surfaceportions of the inner and outer closure flaps.

A further object of this invention is to provide a novel multi-ply bagof the type which includes an inner liner and an outer wrapper, the bagbeing particularly characterized in a bottom construction including afirst folded inner closure flap and an overlying outer closure flap, theouter closure flap including a pair of slits in the inner linerterminating at a bottom edge of the bag and defining with a fold line agenerally rectangular flap section, the flap section being folded awayfrom the bottom edge of the bag to expose an inner surface portion ofthe wrapper of the outer closure flap and an outer uncoated surfaceportion of the inner liner, and adhesive securing these uncoated surfaceportions to the inner closure flap to the exclusion of coating materialon the inner surface of the liner whereby an efiicient and strong sealof the bag bottom is effected.

A further object of this invention is to provide a novel apparatus forforming multi-ply bags of the type described including means for feedingat least an inner web and an outer web in a predetermined direction oftravel along a predetermined path, severing means positioned adjacentthe inner web for forming a foldable flap section in the inner of thewebs, means for deflecting the flap section from the plane of the innerweb prior to the formation of the webs into a multi-ply bag, and meansfor forming the webs into a multi-ply bag having a bottom constructionwhich includes inner and outer closure flaps with the foldable flapsection forming a portion of the outer closure flap and exposinguncoated portions of the liner thereof to the inner closure flap duringthe formation of the bag bottom.

A further object of this invention is to provide a novel method offorming a multi-ply bag of the character described by performing thesteps of advancing inner and outer webs along predetermined paths inpredetermined directions of travel, slitting the inner web to formtherein a generally rectangular foldable flap section, creasing the flapsection along a line normal to the direction of travel to cause the flapsection to deflect out of the plane of the inner web, folding the flapsection in a direction opposite to the direction of travel of the webs,and forming the webs into a bag having a bottom construction formed ofan inner closure flap and an outer closure flap with the foldablesection forming a portion of the outer closure flap and exposinguncoated surface portions of the liner in the area of the outer closureflap to the inner closure flap to effect an extremely strong adhesiveseal between the closure flaps.

With the above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following detailed description, the appended claims and theseveral views illustrated in the accompanying drawings.

In the drawings:

FIGURES l-A and 1B are fragmentary diagrammatic perspective matchingviews of an apparatus constructed in accordance with this invention, andillustrate means for forming a plurality of foldable flaps in a linerweb in accordance with a preferred form of this invention and also showssimilar foldable flaps being formed in a wrapper web in accordance withanother embodiment of the invention prior to the unification of the websinto a two-ply web and the formation thereof into multiply bags. 3

FIGURE 2 is a top plan view of a blank assembly of this invention, andillustrates a liner blank overlying a wrapper blank and a foldable flapformed in the bottom 'area of the liner blank.

FIGURE 3 is a top plan view of the blank assembly of FIGURE 2 with partsbroken away for clarity after the blank assembly has been folded intotube form, and illustrates staggered longitudinal seams of the bag.

7 FIGURE 4 is a fragmentary top vplan view of the flattened compositetube of FIGURE 3, and illustrates the bag bottom after a pair of tabshave been folded toward each other in a common plane and the foldableflap has been folded to expose a portion of an outer closure flap.

FIGURE 5 is a fragmentary top plan view of the composite tube of FIGURE4, and illustrates the finally folded position of an inner closure flapof the bag bottom.

FIGURE 6 is a fragmentary top plan view of the completed multi-bag ofthis invention, and illustrates the overfolding of the outer closureflap int'o overlying relationship with the first folded inner closureflap.

FIGURE 7 is an enlarged fragmentary sectional view taken along line 7-7of FIGURE 6 and clearly illustrates the folded flap section of the outerclosure flap which effects bonding between the closure flaps to theexclusion of coating material on the inner surface of the inner liner.

FIGURE 8 is a fragmentary top plan view of another blank assembly,similar to the blank assembly of FIG- URE 2, and illustrates fiapsformed in a bottom area of both an inner liner and an outer wrapper.

FIGURES 9 through 12 are fragmentary top plan views of the blank ofFIGURE 8 after the same has been folded into tubular form, andprogressively graphically depict the folding of the composite tube toform the finally completed Lbag bottom construction of FIGURE 12. FIGURE13 is an enlarged fragmentary sectional view taken along line 1313 ofFIGURE 12, and illustrates the foldable flaps of inner and outer closureflaps of the bags folded to achieve an adhesive bonding of the bagbottom to the exclusion of coating material on an inner surface of theinner liner.

Referring to FIGURES l-A and l-B of the drawings, an apparatusconstructed in accordance with this invention is generally referred toby the reference numeral and includes means (not shown) for supporting aroll 21 of liner material from which a liner web 22 is drawn and fed bymeans (also not shown) from right-to-left as viewed in these figures,and a roll 23 of outer or wrapper material from which an outer wrapperweb 24 is drawn and advanced. The inner or liner web 22 and the outer orwrapper web 24 are fed in the direction of the headed arrows of FIGURES1-A an 1-B at synchronous speeds toward a conventional bag bottomforming machine 25 (FIGURE 1-A) which forms the webs 22, 24 into bags ina manner to be described more fully hereafter.

The liner web 22 is of a grease-proof type which may be, for example,paperstock material coated upon an inner surface with polyethylene orsimilar coating material M indicated by stippling in FIGURES l-A and1-B. The liner web 22 is drawn beneath the periphery of a driven roll 26having a shaft 27 coupled at one end portion to a conventional universalgear box 28. A main shaft 30 rotates the shaft 27 and the roller 26 in aclockwise direction as viewed in FIGURE 1-B to impart similar clockwiserotation to a gear 31 carried by an end portion of the shaft 27 oppositethe gear box 28. The shaft 27, as well as other shafts and components ofthe apparatus 20 to be described hereinafter, is mounted in aconventional manner to the framework (not shown) of the apparatus 20.The liner web 22 is drawn :beyond the roller 26 and beneath a cyclicallyoperated first severing means 32 which forms a pair of slits 33, 34- inthe liner web 22 in substantially parallel relationship to each otherand to longitudinal edge portions (unnumbered) of the liner web 22. Thesevering means 32 comprises a plurality of cutters 35-38 carried by ashaft pivotally supported at opposite ends thereof to the framewark (notshown) of the apparatus 20. The cutters 35 through 38 are identical andeach includes a split collar 41 axially and circumferentially adjustableon the shaft 40 and secured in any relative position on the shaft 40 bya fastener 42 in a conventional manner. Each of the collars 41 carries ablade 43 having a cutting edge (unnumbered) directed toward and normallyspaced from the liner web 22.

The slits 33, 34 are formed by the cutters 35, 36 each time the shaft 40is rocked in a counterclockwise direction in a manner to be describedmore fully hereinafter. In accordance with a preferred form of theinvention, the cutters 37, 38 and the blades 43 carried thereby areadjusted to a position by the fasteners 42 to prevent the formation ofslits in the Web 22 except in a manner to be later described in theconsideration of a secondary embodiment of the invention.

The first severing means 32 is actuated by drive connecting means 45coupled to the gear 31 secured to the shaft 27. The drive connectingmeans 45 includes a gear 46 in mesh with the gear 31 and a gear 47carried by a shaft 48 journalled in a conventional manner to theframework (not shown) of the apparatus 20. The shaft 48 carries aneccentric or cam 50 having a cam surface 51 along which rides a camfollower 52 in the form of a roller carried by an arm 53 fixed to theshaft 40. The arm 53 is normally biased in a counterclockwise directionas viewed in FIGURE 1-B of the drawings by a spring 54 connected betweenan integral portion 55 of the arm 53 and a portion 56 of the apparatusframework. When the high side of the cam 50 is in contact with the camfollower 52, the blades 43 of the cutters 35, 36 are maintained out 'ofcontact with the liner web 22. However, as the low side of the cam 50contacts the follower 52, the arm 53 is rocked momentarily in acounterclockwise direction by the springs 54 to form the slits 33, 34 inthe liner web 22.

The drive connecting means 45 also imparts movement to a second severingmeans 57 which forms a slit 58 between the slits 33, 34 and generallynorm-a1 thereto.

. The second severing means 57 includes a roll 60 carrying a cuttingblade 61. The cutting blade 61 is of a length generally equal to thedesired length of the slit 58 and is adjustably mounted in aconventional manner on the roll 60 for securement in any axial desiredposition, and is also preferably adjusted by means not shown for spac-.ing the blade 61 at a selected annular relationship relative to creasingmeans 62 in the form of a creasing blade similarly adjustably carried bythe roll 60 in generally parallel relationship to the blade 61. Thecreasing blade 62 forms a crease line 63 between the slits 33, 34 asshown in FIGURE 1-B of the drawings. The blades '61 and 62 cooperatewith a back up roll 64 underlying the liner web 22 adjacent the roll 60.The back up roll 64 preferably includes a rubber or similar elasticinsert against which the blades 61, 62 contact after respectivelypenetrating the liner web 22 to form the slit 58 and bearing against theliner web to form the crease or fold line 63. The roll 64 is driven by agear 65 carried by the shaft 48 of the drive connecting means 45 and agear 66 connected to one end of a shaft 67 of the roll 64. An oppositeend of the shaft 67 carries a gear 68 in mesh with a gear 7t) carrriedby a shaft 71 of the roll 60 to effect rotation of the rolls 64 and 60in the directions indicated by the headed arrows in FIGURE l-B.

During the rotation of the roll 60 by the drive connecting means 45 inthe manner clearly illustrated in FIGURE 1B, the slit 58 is first formedbetween the slits 33, 34 freeing a leading edge of a generallyrectangular foldable flap or section 72 of the liner web 22. Thisfoldable flap 72 is thereafter deflected slightly out of the plane ofthe liner web 22 as shown in FIGURE 1-B by the formation of the creaseor fold line 63. This deflection of the foldable flap 72 out of theplane of the liner web 22 allows the flap 72 to be reversely folded in adirection opposite to the direction of web travel about the fold line 63by folding means 75 (FIGURE 1-A) to be described more fully hereafter.

After the web 22 has been slit and creased to form the foldable flap 72and a plurality of additional identical flaps all referred to by thereference numeral 73 have been formed, the web is guided over a roll 74,beneath a roll 76, beneath another roll 77, and over a roll 78 at whichthe inner web 22 is united with the outer Web or wrapper 24. An adhesiveapplying mechanism 80 (FIG- URE l-B) of a conventional construction ispositioned beneath and slightly downstream of the roll 76. The adhesiveapplying mechanism includes a reservoir 81 housingsuitable water-solubleadhesive A in which is immersed a roll 82 rotatable in a clockwisedirection by a driving connection with the main shaft 30 (not shown). Ametering roll 83 meters the adhesive A upon the periphery of the roll 02which is thereafter transferred to an applicator roll 84 in a desiredpattern. The desired pattern of adhesive on the applicator roll 84 istransferred to the uncoated surface (unnumbered) of the liner web 22 forsubsequently adhering the liner web 22 to the wrapper web 24 uponunification thereof at the roll 78.

The folding means '75 (FIGURE 1-A) includes an angular plate member 86fixed to adjustable collars 87 which are in turn adjustably secured to ashaft 88 by radial set screws (unnumbered). The shaft 88 is in turnfixed to a portion 90 of the framework (not shown) of the apparatus 20.The plate member 86 includes a plate portion 91 positioned generallynormal to the axis of the roller 78 and joined by an integral edge 92 toa plate portion 93 contoured to the configuration of the liner web 22 asit contacts, passes about and passes beyond the roll 78. The edge 92 ofthe plate member 86 is positioned slightly above the upper coatedsurface of the liner web 22 and beneath the leading edge of the foldablefiaps 72, 73 defined by the slit 58. As the foldable flaps 72, 73contact the edge 92 of the angular plate member 86, these flaps arefolded in a generally clockwise direction about their associated creaseor fold lines 63 and are urged to a plane generally parallel to theplane of the liner web 22 by the plate portion 93. However, upon passingbeyond the portion 93 of the plate member 86 the foldable flaps 72, 73rebound slightly, as shown by the leftmost flap 73 of FIGURE 1-A, due tothe natural resiliency of the material from which the liner web 22 isconstructed. Thus, as each of the foldable flaps 72, 73 pass beyond thefolding means 75, the fold lines 63 associated with each foldable flapare leading while the slit or edge 58 of each flap is in a trailingposition. Each of the foldable flaps 72, 73 is assured of beingmaintained in this position by a plow or former 95 having a curved edge96 aligned with the flaps 72, 73. As the flaps 72, 73 pass beneath thecurved leading edge 96 of the plow 95, the flaps 72, 73 are intimatelyurged into overlying relationship to the liner web 22 as the liner web22 and the wrapper web 24 are formed about the former 95 toward atubular configuration prior to being fed into the mechanism 25.

The outer wrapper web 24 is operated upon by the apparatus in much thesame manner as the liner web 22. However, as opposed to the liner web22, the wrapper web 24 is uncoated upon an innermost surface thereof(the upper surface of FIGURE 1-B) and carries indicia I (FIGURE 1A)indicated by the stippling which may, for example, be in the form ofprinted matter, advertising, etc. The wrapper web 24 is guided by pairsof rolls 97, 98 (FIGURE l-B) beneath the periphery of a roll 100corresponding to the roll 26 beneath which the liner web 22 is drawn.The roll 100 is rotated in the direction of the headed arrow by thedriving connection of its shaft 101 with the main shaft 30 through aconventional gear box 102. After passing beyond the periphery of theroll 100, the wrapper web 24 is guided to a generally vertical plane bya roll 103 journaled by a shaft (unnumbered) to a portion 104 of theapparatus framework (not shown). As the wrapper web 24 is drawn betweenthe roll 103 and the roll 78, first severing means 105 are operative toform a pair of slits 106, 107 in the outer wrapper 24.

The severing means 105 is substantially identical to the severing means32 and includes a shaft 108 carrying a plurality of cutting means orcutters 110-113 each identical to the cutters 3538 of the first severingmeans 32, and a description of the former is therefore consideredunnecessary for a complete understanding of this invention. However, itwill be noted that the slitters or cutters are four in number but onlytwo are operative to form the pair of slits 106, 107 and the distancebetween the cutters forming the slits 106, 107 is further than thedistance between the cutters 35, 36. Thus, the slits 33, 34 arepositioned between the slits 106, 107 as will appear more fullyhereafter.

The severing means 105 is cyclically operated by drive connecting meansincluding a gear 116 carried by an end portion (unnumbered) of the shaft101 remote from the gear box 102. The gear 116 is in mesh with a gear117 which in turn meshes with and drives a gear 118 fixed to a shaft 120suitably journaled in the framework of the apparatus 20. The shaft 120carries a cam 121 having a cam surface 122 upon which rides a cam rolleror follower 123 rotatably fixed to an arm 124. The arm 124 is fixed tothe shaft 108 and an opposite end portion 125 of the arm 124 is biasedby a spring 126 fixed to the portion 104 of the framework for normallyurging the shaft 108 and the cutters 110-113 fixed thereto in aclockwise direction as viewed in FIGURE 1-A of the drawings. As the camfollower or roller 123 approaches the low side of the cam, the spring126 rocks the shaft 108 clockwise and the cutters 110, 111 form theslits 106, 107 respectively.

The apparatus 20 also includes severing means 130 downstream from thesevering means 105, but in a preferred form of this invention, thesevering means 130 are inoperative and no cutting of the outer wrapperweb 24 thereby is effected. The severing means 130 will, therefore, bemore fully described hereinafter.

After the slits 106, 107 have been formed in the outer wrapper web 24and the outer wrapper web 24 has been united with the adhesively coatedliner web 22, the twoply web is folded by the former 95 toward a tubularconfiguration and the bottom formed by the bottom forming mechanism 25.The eventual line of cut-off is indicated by the line XX of FIGURE 1A,and depending upon the particular construction of the mechanism 25 and/or the former 95, the adhesively joined webs 22, 24 can either beconsecutively cut along the line X-X prior to being formed into agenerally tubular configuration or after a tube has been formedtherefrom, with the latter being the preferred construction.

The mechanism 25 is, as was heretofore noted, conventional inconstruction and may form either a square bottom construction or asatchel bottom construction from the webs 22, 24. In accordance withthis invention a square bottom construction is formed in each multi-plybag formed from each blank assembly (FIGURE 2) generally referred to bythe reference numeral 140, formed upon the severance of the webs 22, 24along the consecutive line of severance XX. Each blank assemblyconstructed in accordance with this invention includes a liner blank 142formed from the material of the liner web 22 and a wrapper blank 144formed from the material of the outer wrapper web 24. The liner blank142 is illustrated in FIGURE 2 above the wrapper blank 144 with thecoating material M being exposed.

The liner blank 142 is of a generally rectangular configuration andcomprises a pair of longitudinal edges 145, 146 a top or trailing edge147 and a bottom or leading edge 148 formed when the webs 22, 24 aresevered along the severance line X-X of FIGURE 1A. The wrapper blank 144is similarly substantially rectangular in outline and includeslongitudinal edges 150, 151 staggered with respect to the respectivelongitudinal edges 145, 146 of the liner blank 142, a top edge 1'52, anda bottom edge 153. The blanks 142, 144 are illustrated as a tubularassembly 160 in FIGURE 3 to clearly illustrate the adhesive A applied bythe adhesive applying mechanism 80 of FIGURE 1-B securing the overlappededges 145, 146 of the liner blank to each other and similar adhesive Aapplied by conventional means (not shown) between the overlapped edges150, 151 of the wrapper blank 144. Adhesive is also positioned betweenthe blanks 142, 144 at the shaded areas 155, 156 adjacent the bottomedges 148, 153 and the shaded area 157 adjacent the top edges 147, 152to maintain the blanks 142, 144 in assembled relationship during theformation thereof into the tube or tube assembly 160 and the subsequentformation of the latter into a multi-ply square bottom bag showncompletely formed in FIGURE 6 and referred to by the reference numeral200.

The liner blank 142 includes three longitudinal fold lines 161, 162 and163 which overlie corresponding longitudinal fold lines 164, 165 and 166respectively in the wrapper blank 144. The fold lines 161166 form one ofa pair of side gussets 167 in the tube 160 as well as in the multi-plybag 200. Similar longitudinal fold lines 171, 172 and 173 of the linerblank 142 overlie and are in alignment with respective longitudinal foldlines 174, 175 and 176 of the wrapper blank 144. The fold lines 171-176are foldable in a conventional manner to form a side gusset 177 of thetube 160 and the bag 200 in a well known manner.

A front wall 168 of the liner blank 142 is'disposed between the foldline 173 and'the fold line 161 while a similar front wall 178 of theouter blank 144 is disposed between the fold line 176 and the fold line164.

A rear wall 180 of the liner blank 142 is defined between the fold lines171, 163 while a similar rear wall 181 (FIGURE 7) of the wrapper blank144 is set off between the fold lines 166 and 174.

A pair of transverse fold lines 182, 183 in the liner blank 142 overlierespective transverse fold lines 184, 185 of the wrapper blank 144. Thefold lines 182, 183 extend between the longitudinal edges 145, 146,while the fold lines 184, 185 extend between the longitudinal edges 150,151.

A pair of fold lines 186, 187 of the liner blank 142 diverge from theintersection of the fold lines 162, 182 at an angle of approximately 90degrees and terminate at the bottom edge 148. The fold lines 186, 187overlie corresponding fold lines 190, 191 respectively of the wrapperblank 144.

Another pair of fold lines 192, 193 of the liner blank 142 diverge fromthe intersection of the fold lines 172, 184 at an angle of approximately90 degrees and terminate at the bottom edge 148 of the liner blank 142.The fold lines 192, 193 overlie respective fold lines 194, 195 of thewrapper blank 144.

A fold line 197 of the wrapper blank 144 extends between the juncture ofthe longitudinal edge 151 and the fold line 185 to the bottom edge 153of the wrapper blank 144 at a point at which the longitudinal edge 146of the liner blank 142 merges with the bottom edge 148 thereof.

The liner blank 142 is provided with a pair of slits 203, 204 openingoutwardly through the bottom edge 148. The slits 203, 204 correspond tothe respective slits 33, 34 in the liner web 22 (FIGURE 1-B), while anedge portion 205 of the bottom edge 148 corresponds to the edge formedby the slit 58. A fold or crease line 206 in spaced parallelrelationship to the edge portion 205 corresponds 8 to the crease or foldline 63 of the liner web 22, and defines with the slits 203, 204 and theedge portion 205, a generally rectangular foldable flap or section 207corresponding to the foldable flaps 72, 73 of FIGURES 1-A and 1-B of thedrawings.

The wrapper blank 144 includes a pair of slits 216, 217

corresponding to the slits 106, 107 formed in the wrapper web 24 (FIGURElA). The slits 216, 217 similarly open outwardly of the bottom edge 153of the wrapper blank 144, and are both spaced further apart from eachother and are longer than the slits 203, 204 of the liner blank 142. Theslits 216, 217 define a flap portion 218 with an edge portion 219 of thewrapper blank edge 153 which is generally larger in area than thefoldable flap 207 of the liner blank 142.

After the bank assembly of FIGURE 2 has been formed into the tube ofFIGURE 3 the folding mechanism 25 progressively folds the bottom portionof the tube 160 in the manner illustrated in FIGURES 4 and 5 of thedrawings to form the completely folded bottom construction 225 of themulti-ply bag 200 of FIGURE 6. The initial folding of tube 160 isillustrated in FIGURE 4 after the side gussets 167, and 177 have beenformed and the bottom has been folded to define opposing closure tabs230, 231, an inner first folded closure flap 232 and an outer lastfolded closure flap 233. Since the foldable flap 207 of the liner 142was reversely folded about the fold or crease line 206 in the manner ofthe flaps 72, 73 prior to the overfolding of the tabs 230 and 231, theoutermost uncoated surface OS (FIGURE 4) of the liner 142 in the area ofthe flap 207 is exposed between the closure tabs 230, 231 while an inneruncoated surface IS of the wrapper 144 in the area of the flap 218 issimilarly exposed.

After adhesive has been applied to the tabs 230, 231, the inner closureflap 232 and the surfaces OS and IS of the respective foldable flaps 207and 218, the closure flap 232 is folded to the position shown in FIGURE5 in overlying adhesive contact with the tabs 230, 231. The outerclosure flap 233 is then overfolded to the position illustrated inFIGURE 6 with the surfaces OS and IS of the respective portions 207 and218 in adhesive overlying contact with the exterior surface of the innerclosure flap 232. As was heretofore noted, the adhesive employed ineffecting the seal of the bag bottom 225 is of a water-soluble type,such as animal glue. Such watersoluble adhesives do not readily adhereto impermeable material, such as the polyethylene coating M and do notset rapidly, if at all, because of the inability of the nonporousmaterial to absorb the water of the water-soluble adhesive. However, bythe overfolding of the flap 207 to shield a major portion of thematerial M at the bottom 225 (FIGURE 5) and to expose both of the porousuncoated surfaces OS and IS, substantially the entire area of the outerclosure flap 233 is brought into adhesive bonding contact with the innerclosure fiap 232 in the absence of appreciable coating material M.

Referring to FIGURE 7 of the drawings, the effectiveness of the sealachieved by this invention at the bottom 225 of the multi-ply bag 220 isclearly evident. The uncoated inner surface IS coated with water-solubleadhesive A (also FIGURE 5) is in intimate adhesive contact with theouter surface of the inner closure flap 232 while the outer uncoatedsurface OS of the foldable flap 207 is similarly coated withwater-soluble adhesive and is in sealing contact with the outer surfaceof the inner closure flap 232. The relatively impermeable nonporouscoating material M is, however, shielded by the overfolded flap 207. Inthis manner, a seam is effected in the bag bottom 225 between largeruncoated area portions thereof than heretofore provided in conventionalbag bottom structures.

Referring to FIGURES 8 through 13 of the drawings, and FIGURE 8 inparticular, another blank assembly 300 is illustrated and correspondssubstantially identical- 9 1y to the blank assembly 140 except for twovariations to be described fully hereafter. Except for these variationsthe blank assembly 300 is numbered identically to the blank assembly 140of FIGURE 2.

The blank assembly 300 is formed from inner or liner webs and outer orwrapper webs corresponding to the Webs 22 and 24 respectively of FIGURES1A and 1-B. As in the case of the blank assembly 140, a liner blank 301(FIGURE 8) of the blank assembly 300 includes a pair of slits 303, 304opening through a bottom edge 305 which is substantially coextensivewith a bottom edge 306 of an outer or wrapper blank 307 except for anedge portion 308 between the slits 303, 304 projecting beyond the bottomedge 306 of the wrapper blank 307. A crease or fold line 310 joins theslits 303, 304 remote from the edge portion 308. The slits 303, 304 arepositioned between a pair of slits 311, 312 formed in the wrapper blank307 and opening through the bottom edge 306 thereof.

The slits 303, 304. the edge portion 308 and the crease or fold line 310of the liner blank 301 define a generally rectangular foldable flap orsection 315 corresponding to and formed in the same manner as thefoldable flaps 72, 73 of FIGURES 1-A and 1B with one exception i.e., thefoldable flap 315 projects beyond the bottom edge 306 of the wrapperblank 307. This offsetting or projecting of the foldable flap 315 beyondthe bottom edge 306 of the wrapper blank 307 is formed by the mechanism25 after the web forming the liner blank 301 has been first perforatedby a mechanism 320 (FIGURE 1-B). The mechanism 320 includes a'rollerbacking roll 321 having a yieldable peripheral surface and an upper roll322 carrying a pair ofperforating elements 323, 324 spaced from eachother a distance corresponding to the distance between the slits 303,304. The roll 322 is driven in a conventional manner by the shaft bymeans not shown to form a plurality of perforations in the liner web toeach side of the foldable flap 315. The element 323 perforates a portion316 of the liner blanks 301 between the slit 303 and a longitudinal edge317 of the liner blank, while the element 324 perforates a portion 318of the liner 301 between the slit 304 and an edge 320 of the linerblank. The lines of perforations 316, 318 and the edge 303 of the flap315 combine to form the bottom edge 305 of the liner blank 301. Thelines of perforation 316, 318 merely weaken the liner web and themechanism 25 severs the same after the liner web has been joined withthe wrapper web by advancing a leading portion of the unified webs at afaster speed than a trailing portion. This is accomplished by leadingand trailing pairs of rollers (not shown) of the mechanism 25. Theleading pair of rollers is driven more rapidly than the trailing pair ofrollers and the unified webs are tensioned and ruptured along the linesof perforations 316, 318 to form the individual blank assemblies 300.The outer or wrapper blank 307 is similiarly perforated by meanscorresponding to the means 320 which perforate the bottom edge 306 ofthe wrapper blank 307, causing the simultaneous severance thereof duringthe aforementioned tensioning of the unified webs.

The bottom edge 306 of the wrapper blank 307 is formed by perforatedportions (unnumbered) to either side of a pair of slits 330, 331 in thewrapper blank 307 opening outwardly through the bottom edge 306 thereof.The slits 330, 331 are joined by a crease or fold line 332 parallel toand spaced from a straight out edge portion 333 of the bottom edge 306.The slits 330, 331, the crease line 332 and the straight out edge 333define a generally rectangular foldable flap or section 335,corresponding to the foldable flap or sect-ion 315 in the liner blank301.

The slits 330, 331 are formed in the wrapper blank 307 by the cutters112, 113 of the severing means 105 10 (FIGURE 1-A) in the mannerheretofore described with respect to the cutter-s 110, 111. The creaseline 332 and the straight cut edge 333 are formed by the severingmechanism 130 as follows:

The severing mechanism 130 includes a backup roll 436 carrying a gear437 in mesh with a gear 438 carried by the shaft 120 and driven by themeans in the manner heretofore described. The roll 436 is identical tothe roll 64 of the severing means 57 and includes a gear correspondingto the gear 68 in mesh with a gear corresponding to the gear 70 (notshown) for driving a roll 440. The roll 440 includes a cutting element441 for transversely severing the wrapper blank 307 while in one formalong the edge 333 between the cut lines 330, 331 and a creasing element442 for forming a crease corresponding to the crease 332 of FIGURE 8.

Folding means 443 corresponding to the folding means 75 include anelement 444 adjustably supported on a shaft 445 secured at opposite endportions to a portion 446 of the framework (not shown) of the apparatus20. The element 444 folds each of the foldable flaps 335 in a. directioncorresponding to the folding of the flaps 72, 73, i.e., a directionopposite to the direction of wrapper web travel whereby the flap 335 isunderfolded in the manner best illustrated in FIGURES 9-11 of thedrawings.

In FIGURE 9 of the drawings, the flap 335 is shown underfolded in adirection away from the bottom edges 305, 306 of the respective blanks301, 307 after the same have been formed into a tube or tube assembly340 and separated from web to blank form in a manner heretoforedescribed. The underfolding of th flap 335 exposes an outer uncoatedrectangular surface portion of the liner blank 301 which is shown shadedin FIGURE 9 prior to the folding of the tube 340 and is generallyreferred to by the reference numeral 336. The folded flap 315 similarlyexposes an uncoated inner surface portion 337 (FIGURE 10) of the outerwrapper shown shaded in FIGURE 10, and also exposes an uncoated outersurface 338 of the liner in the area of the folded flap 315.

The tube 340 is folded by the mechanism 25 in a conventional manner toform a square bottom 345 (FIGURES 12 and 13) of a m-ulti-ply bag 350 bythe apparatus 25 by first in folding a pair of closure tabs 341, 342(FIGURE 10), thereafter folding an inner closure flap 343 into overlyingrelationship to the tabs 341, 342 (FIGURE 11) and finally folding anoutermost closure flap 344 (FIGURE 12) into overlying relationship withthe inner closure flap 343.

In the completed form of the bag bottom 345, as is best illustrated inFIGURE 13 of the drawings, the uncoated inner surface portion 337 of theflap 344 is brought into overlying sealing relationship with the outersurface portion (unnumbered) of the inner closure flap 343 while theuncoated inner surface portion 338 of the folded fiap 315 is broughtinto overlying sealing engagement with the uncoated outer surfaceportion 336 of the inner closure flap 343. This construction permitswater-soluble adhesive to be absorbed by two opposing uncoated surfaceportions (336, 338) of the liner 30-1 and an uncoated surface portion337 of the wrapper 307 with an exterior surface portion of the wrapperin the area of the flap 343 which may or may not be coated with materialwhich is relatively impermeable to the water of a water-solubleadhesive. In this manner, a greater porous uncoated area of each of theliner and wrapper blanks is presented to a water-soluble adhesive foreffecting the setting-up thereof in a shorter period of time thanheretofore provided for in conventional bag bottom constructions, and inaddition, the greater exposure of the porous permeable material effectsa more permanent and reliable seal in such construction.

From the foregoing, it will be seen that novel and advantageousprovisions have been made for carrying out the desired end. However,attention is again directed 1 l to the fact that additional variationsmay be made in this invention without departing from the spirit andscope thereof as defined in the appended claims.

I claim:

1. A web assembly for forming a blank assembly from which is formed bagsof the type including an inner tube, an outer tube and a bottom whereinthe bottom has an outer tube outer flap portion secured to an outer tubeinner flap portion through a slot of the inner tube whereby a seal isperfected irrespective of the sealing characteristics of the inner tubecomprising inner and outer superimposed webs of sheet material adaptedto form respective inner and outer tubes of a multi-ply bag, said webshaving opposite longitudinal edge portions, at least a single pair ofslits in one of said webs generally parallel to the longitudinal edgeportions thereof, a slit between the pair of slits and definingtherewith a foldable flap of said one web, and said foldable flap beingfolded to a position generally overlying a portion of said one webthereby forming a slot through which a portion of the other of said websis exposed.

2. A tube assembly from which is formed a bag of the type including aninner tube, an outer tube, and a bottom wherein the bottom has a firstouter tube portion secured to a second outer tube portion through anopening of the inner tube whereby a seal is perfected irrespective ofthe sealing characteristics of the inner tube comprising inner and outerbag tubes of sheet material having upper and lower portions terminatingin respective terminal edges, at least a single pair of slits in theinner bag tube opening through the terminal edge of the inner bag tube,a fold line between the pair of slits, said fold line, slits and aportion of the inner tube terminal edge defining a foldable flap beingreversely folded and directed away from said terminal edges to expose aportion of the outer tube.

3. A tube assembly from which is formed a bag of the type including aninner tube, an outer tube, and a bottom tube, wherein the bottom hasfirst inner and outer tube portions secured to second inner and outertube portions respectively through first and second slots in the tubeportions whereby a seal is perfected irrespective of the sealingcharacteristics of one of the inner and outer tubes of sheet materialhaving upper and lower portions terminating in respective terminaledges, at least a pair of slits in the inner and outer bag tubes openingthrough the respective terminal edges thereof, a fold line between eachof the pairs of slits to define with each pair of slits a foldable fiap,and said foldable flaps each being reversely folded and directed awayfrom said terminal edges to expose portions of the inner and outer tubesthrough openings defined by the reversely folding of the foldable flaps.1

4. A tube assembly from which is formed a bag of the type including aninner tube, an outer tube, and a bottom wherein the bottom has a firstinner tube portion secured to a second inner tube portion through anopening of the outer tube whereby a seal is perfected irrespectiveof thesealing characteristics of the outer tube comprising inner and outertubes of sheet material having upper and lower portions terminating inrespective terminal edges, at least a single pair of slits in the outertube opening through the terminal edge of the outer tube, a fold linebetween the pair of slits, said fold line, slits and a portion of theouter tube terminal edge defining a foldable flap, and said foldableflap being reversely folded and directed away from said terminal edgesto expose a portion of the inner tube through an opening of the outertube defined by the reversely folded foldable flap.

5. In a multi-ply bag bottom construction of the type including at leastinner liner and outer wrapper tubes folded to define a pair of inneropposed tabs, an inner flap folded. into overlying relationship to thetabs, and an outer flap folded into overlying relationship to the innerflap, the improvement comprising a pair of spaced slits in the innerliner of the outer flap, said slits opening through a terminal edge ofthe inner liner, a fold line joining said slits remote from the innerliner terminal edge, said slits and fold line defining a foldable flap,said foldable flap being folded away from the inner liner terminal edgeto expose the inner surface of the outer flap to the outer surface ofthe inner flap, and adhesive between said surfaces.

6. In a multi-ply bag bottom construction of the type including at leastinner liner and outer wrapper tubes folded to define a pair of inneropposed tabs, an inner flap folded into overlying relationship to thetabs, and an outer flap folded into overlying relationship to the innerflap, the improvement comprising a pair of spaced slits in the outerwrapper of the inner flap, said slits opening through a terminal edge ofthe outer wrapper, a fold line joining said slits remote from the outerwrapper terminal edge, said slits and fold line defining a foldableflap, said foldable flap being folded away from the terminal edge toexpose the outer surface of the inner liner of the inner flap to theinner surface of the inner liner of the outer flap, and adhesive betweensaid surfaces.

7. In a multi-ply bag bottom construction of the type including at leastinner liner and outer wrapper tubes folded to define a pair of closureflaps, the closure flaps including an inner closure flap and an outerclosure flap folded into overlying relationship to the inner closureflap, the improvement comprising a section of the outer wrapper of theinner flap folded away from a bottom edge of the bag to expose an outersurface portion of the inner liner at the inner flap to an outer surfaceportion of a section of the inner liner of the outer flap folded awayfrom the bottom edge whereby said surface portions are in opposedrelationship, said folded sections further exposing an inner surfaceportion of the outer wrapper at the outer flap to an outer surfaceportion of the outer wrapper at the inner flap, and adhesive securingsaid closure flaps together at said surface portions.

8. In a multi-ply bag bottom construction of the type including aplurality of tubes having bottom edges and being folded to define abottom having a first flap, a second fiap folded into overlyingrelationship to the first flap, and said first and second flaps beingmulti-ply structures each including innermost and outermost flapportions each having innermost and outermost surfaces, the improvementcomprising means exposing the innermost surface of the outermost flapportion of the second flap to the outermost surface of the outermostflap portion of the first flap, said exposing means being defined by thereverse folding of the innermost flap portion of the second fiap intooverlying relationship upon itself, and means securing said first andsecond flaps to each other through said exposing means.

9. In a multi-ply bag bottom construction of the type including aplurality of tubes having bottom edges and being folded to define abottom having a first flap, a second flap folded into overlyingrelationship to the first flap, and said first and second flaps beingmulti-ply structures each including innermost and outermost flapportions each having innermost and outermost surfaces, the improvementcomprising means exposing the outermost surface of the innermost flapportion of the first flap to the innermost surface of the innermost flapportion of the second fiap, and means securing said first and secondflaps to each other through said exposing means.

10. In the multi-ply bag bottom construction as defined in claim 8wherein the bottom terminal edges of said plurality of tubes arealigned, and said exposing means is a slot formed in the innermost flapportion of the second flap opening toward and terminating at theterminal edge of the tube defining the innermost flap portions.

11. In the multi-ply bag bottom construction as defined in claim 8wherein said exposing means is a tab formed from the material of theinnermost flap portion of the second flap, said tab including a freeedge, and said tab 13 being folded with the free edge thereof directedaway from said bottom terminal edges.

12. In the multi-ply bag bottom construction as defined in claim 11wherein said tab includes first and second surfaces, one of said tabsurfaces being adhesively compatible with the outermost surface of theoutermost flap portion of the first fiap, the other of said tab surfacesbeing adhesively compatible with the outermost surface of the outermostflap portion of the first flap, and said other tab surface being inopposed overlying adhesively secured relationship to the outermostsurface of the outermost flap portion of the first flap.

13. In the multi-ply bag bottom construction as defined in claim 9wherein the bottom terminal edges of said plurality of tubes arealigned, and said exposing means is a slot formed in the outermost flapportion of the first flap opening toward and terminating at the terminaledge of the tube defining the outermost flap portions.

14. In the multi-ply bag bottom construction as defined in claim 9wherein said exposing means is a tab formed from the material of theoutermost flap portion of the first flap, said tab including a freeedge, and said tab being folded with the free edge thereof directed awayfrom said bottom terminal edges.

15. In the multi-ply bag bottom construction as defined in claim 9wherein said exposing means further includes additional means exposingthe innermost surface of the outermost flap portion of the second flapto the outermost surface of the outermost flap portion of the firstflap, and said additional exposing means includes a tab formed from thematerial of the innermost flap portion of the second fiap, said tabincluding a free edge and said tab being folded with the free edgethereof directed away from said bottom terminal edges.

16. In the multi ply bag bottom construction as defined in claim 15wherein said first-mentioned exposing means includes a tab formed fromthe material of the outermost flap portion of the first flap, saidlast-mentioned tab including a free edge, and said last-mentioned tabbeing folded with the free edge thereof directed away from said bottomterminal edges.

References Cited by the Examiner UNITED STATES PATENTS 1,633,296 6/1927Tooker et al.

2,078,467 4/1937 Sterling 229--59 2,460,886 2/1949 Hoppe 22959 2,600,4876/1952 Craig 22959 2,903,947 9/ 1959 Weisshuhn 9335 3,025,768 3/1962Kessler 93-35 FRANKLIN T. GARRETT, Primary Examiner.

JOSEPH R, LECLAIR, Examiner.

1. A WEB ASSEMBLY FOR FORMING A BLANK FROM WHICH IS FORMED BAGS OF THETYPE INCLUDING AN INNER TUBE, AN OUTER TUBE AND A BOTTOM WHEREIN THEBOTTOM HAS AN OUTER TUBE OUTER FLAP PORTION SECURED TO AN OUTER TUBEINNER FLAP PORTION THROUGH A SLOT OF THE INNER TUBE WHEREBY A SEAL ISPERFECTED IRRESPECTIVE OF THE SEALING CHARACTERISTICS OF THE INNER TUBECOMPRISING INNER AND OUTER SUPERIMPOSED WEBS OF SHEET MATERIAL ADAPTEDTO FORM RESPECTIVE INNER AND OUTER TUBES OF A MULTI-PLY BAG, SAID WEBSHAVING OPPOSITE LONGITUDINAL EDGE PORTIONS, AT LEAST A SINGLE PAIR